FA N Ruilin Institute of Aeronautical Materials
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Beijing
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China
金属学报(英文版)
The high-cycle fatigue performance of different microstructures of aluminide coating- superalloy system has been studied at 900℃.The single phase coating of coarse equiaxial grain NiAI(β)has unfavorable eJfect onJatigue life of the coating-superalloy.The fatigue life may shorten if the coating of NiAl(β)was an enrichment of coarse refractory metal grains. While an improvement can be made by dispersing numerous secondary phase particles such as extreme.fine γ′,quasi-σ-phase and others.
关键词:
aluminide coating
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null
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null
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null
Z.L. Zhan
,
*
,
Y.D. He
,
W. Gao
金属学报(英文版)
Nanocrystal ODS (oxide dispersion strengthening) aluminide coatings were produced on a stainless steel and nickel-based superalloy by the pack aluminizing process assisted by ball peening. Pure Al powders and 1% of ultra-fine Y2O3 powders were mixed by ball milling. The ultra-fine Y2O3 powders were dispersed in Al particles. Ball peening welded the Al particles onto the substrate and accelerated the formation of aluminide coating. Nanocrystal ODS aluminide coatings were produced by the outward growth at a much low temperature (below 600℃) in a short treatment time. The effects of the operation temperature and treatment time on the formation of the coatings were analyzed. SEM (scanning electron microscope), AFM (atomic force microscope), EDS (energy dispersive X-ray spectroscopy), XRF (X-ray fluorescence spectrometer) and XRD (X-ray diffraction) methods were applied to investigate the microstructure of the coatings. High-temperature oxidation tests were carried out to evaluate the oxidation resistance of the ODS aluminide coatings.
关键词:
nano-coating
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微米/纳米晶涂层
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球击处理过
韦华
,
孙晓峰
,
郑启
金属学报
通过纯Ni和K465合金表面渗Al涂层中Al原子浓度分布曲线的分析, 考虑到K465合金复杂的化学成分和显微组织, 基于一定的假设, 推导出Wagner修正式,并分别计算了850, 950和1β050℃纯Ni和K465合金表面渗Al涂层中β--NiAl相Ni, Al互扩散系数.计算结果表明:K465合金表面渗Al层中β--NiAl相Ni, Al互扩散系数明显小于纯Ni表面渗Al涂层中β--NiAl 相Ni, Al互扩散系数；与化学计量比β--NiAl相相似, K465合金表面渗Al中β--NiAl相Ni, Al互扩散系数与Al原子浓度有很大的相关性.简要分析了合金元素和析出相对渗Al涂层中β--NiAl相Al, Ni互扩散系数的影响.
关键词:
铝化物涂层
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pack cementation
宋鹏
,
陆建生
,
吕建国
,
张德丰
稀有金属材料与工程
研究比较沉积热障涂层和无热障涂层的镍基高温合金铂改性铝化物涂层在900,1000和1100 ℃空气中高温氧化生成的氧化铝层表面形态和断面结构.发现低铂含量涂层氧化初期热生长层(TGO)表面有放射状裂纹形成和长大,造成氧化铝的局部脱落,并在TGO与铂铝涂层界面形成空洞.涂层900 ℃循环氧化300 h后TGO内部均形成空洞.而在1100 ℃氧化时,TBC陶瓷层的存在改变了两种铂铝涂层TGO的内应力变化趋势,升高温度使TGO厚度迅速增大,涂层寿命迅速下降.
关键词:
铂
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铝化物涂层
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高温氧化
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热生长层
任鑫
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玄兹航
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曹丹凤
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孔令梅
,
朱鹤
机械工程材料
doi:10.11973/jxgccl201506004
采用固体粉末包埋法在高温合金K438表面制备了一种NiZr-CrAl涂层和单渗铝涂层,通过循环氧化动力学曲线分析、形貌观察及物相分析等对比研究了两种涂层在1 000℃下的循环氧化行为.结果表明:单渗铝涂层和NiCr-CrA1涂层均由β-NiAl构成;在循环氧化300 h后,NiCr-CrAl涂层质量增加明显低于单渗铝涂层的;单渗铝涂层表面氧化物由α-Al2O3、NiAl2O4和TiO2混合氧化物组成,涂层出现了明显的NiAl向Ni3Al退化,涂层抗氧化性能下降;而NiCr-CrAl涂层表面氧化物仍由致密的α-Al2O3相构成,涂层中仅出现轻微的退化,表现出优异的抗循环氧化性能.
关键词:
镍基高温合金
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铝化物涂层
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循环氧化
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退化
宋鹏
,
陆建生
,
吕建国
,
张德丰
稀有金属材料与工程
研究镍基高温合金的热障涂层系统中不同铂含量的改性铝化物粘结层在1100 ℃空气中循环氧化和非连续氧化行为及生成的氧化铝层的内应力状态.发现在不同循环氧化条件下,铂铝粘结层表面都形成连续致密的α-Al_2O_3层,并且α-Al_2O_3具有相同的形态和相似的平均厚度.而在非连续氧化初期,Al_2O_3层热生长应力快速增大,在氧化至100 h时内应力出现峰值.同时由于高含量铂促进Al元素的扩散从而改变了涂层力学性能,造成高含量铂涂层中表现较大的内应力,但铂含量不能影响Al_2O_3层中内应力曲线变化趋势.另外,低铂含量涂层γ′-Ni_3Al多沿β-NiAl晶界生成,而高含量铂使涂层晶粒细化,导致γ′-Ni_3Al相呈弥散分布生长,从而可以形成Al元素的"网"状快速扩散通道.
关键词:
铂
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铝化物涂层
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高温氧化
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内应力
